Method for preparing diphenylol methane



Patented Nov. 11, 1952 THANE RobertW. MartimLenox, Mass, assignor to GED-r oral Elect i C mpa a orpor ion" of New Xork No, Drawing. Application June 28, 11951,. Serial-No. 231,151

.Ihis. invention is. c ncerned. w th ameth d. for hrehh ihgdiphe ylol methane ha i the. formu a Mo e particularly h invention relates to. a h r making .dinhehylol, methane which oompnses ie tihsreact on in h p sencelof a at: he acidic tyne catalyst between a meth urea, e, a dimethy lhre mon met lol u ea etc), and. ahexcess oi. ph olwhereinth Ph ol is present in an amount equal teat leastzfi, e,.,g., rom 21 to c r .Inor mole of the latter, per mol oi methylc group, in t methylol ur a.

t. V, ,2 issued November 1. 1931 ow nt e r choir of d methylol u a and phpn e. of a a ueous a ho som on nd containing.introducedgaseouslh ogen ch e, ateht d sc ses th t ider such 9 one th re 1 ohtainedabout a 50% yield o p e hydroxyrhethyll beta- (2 h rouhenzyb urea having he f rmul CHQNHCONHCHMH Uhexpeetecl m I have discover d that con rary i; t the reac ion betweenzthe m thylo nheho and the. urea i a s v n compris ng a excess of thephenol usinga strong acidic-catalyst tor the react onand emp oy ng water, as a dis- Qe in ge-ht. for t e methylol urea: The m ylclurea mployed m y o pr se, o nfithilfihwdillifilihtltil. ur a m h m thy ol urea, T e ri ical ea ure of my inven io appears to.- he the fa that I employ an xcess: o hheholas compared to essentially equimolecula proPQitiQhsof. dimethylol urea and phenol disclosed in the above-mentioned patent. Thus, I may use from 2.5 to 6 or more, for example, 8 to llzgmol rot phenol for eachmol of-methylol group present in the methylol urea; V

The strong acidic type catalysts used may be any one of those well known in the art substantiallynonreactive with any of the reactants, as, for exa'mple, hydrochloric acid, sulphuric acid,

benzene sulfonic acid, toluene sulfonic. acid;

Friedel-Crafts type catalysts '(e; g., BFa, A1613,

ZnClz, etc.) etc. Although these strong-acidsper se maybe employed, generally, I have foundfthat aqueous mixtures of the acids as, for instance, concentrated hydrochloricacid (e. g., about 40% acid), concentratedsulfuric acid (e. g., 50%; sul furic acid, the remainder water): may preferably be employed in the practice of theinventiono The amount of acidic type catalyst used-'isrnot criticalv and may be varied within wide: .lim-its. Generally, on a weight basis I may use from.0.,01- to 5% or more catalyst, e. g., hydrochloricaoid, preferablyin theform of a concentrated aqueous solution as, for instance, aqueous hydrochloric acid containi 40%, by wei ht f H01. ahdha ing a specificgravity of about L2, Lessconc trated acidic solutions may be employed butrg neeralily I prefer to use-the conc n rated ionnz th acidic type catalyst or a, hy o loric a id rahyotherstr ne acid-r m xing. the phe ol the U (e, a, rom 1 to 6 p rts or more .,hy w ght; ner 'par-t of the methy ol urea-hand the t oheaacielca a yst. e mix u e i prefe ably he ted ently at a t p a u e f ea out 35'" t 69 C. and th rea ter heated to the. boiling poin Q hemi tuI r a p i d ra ng fr m abou A. t fihours to e f c compl t react n. ne other method tor preparing the diphcnylolt methane comprises forming a mixture; of the phenol and strong acid catalyst, heating the mixture to about C. and while maintaining the tempera ure of th mix ure a ound thispoih e the he hyl l ur a, for amp e. di-

sneth lcl' area until solution is complete, and

herea ter heatin th e tire mass at elevated te per t res o at reflux mp u es o the mass) to complete the, reaction.

In orde h those. ll d in the art may ter" understan h w he prese inve ti n may be. p ctic d iollowihg ex mple ar g en by as! o l ust a and n y way of limi tion. All parts are by weight;

Example 1 around 45-60" C. during the addition of the dimethylol urea which required about 1 hour. The reaction mixture was stirred about hour after all of the dimethylol urea had been added during which time the temperature dropped to 40 C. The mixture was then heated to 60 C. for 30 minutes, and thereafter 200 ml. of concentrated hydrochloric acid was added and the mixture again heated at 100-102 C. for 1 hour.

The excess phenol and aqueous HCl were distilled off at elevated temperatures at -25 mm. pressure. The pot temperature was taken to 130 C. and the still head temperature was taken to 100 C. The residue left in the distilling flask was poured into two liters of boiling water and stirred vigorously. The aqueous layer was decanted and allowed to cool. The water extraction was again repeated. The residue was then extracted repeatedly with boiling toluene. The crystals which separated from the Water extract and toluene extract totalled 898.5 grams. Recrystallation of this product from water gave about 479 grams of 4,4'-diphenylol methane melting at 154-157" C. This material was identified by infra red absorption spectra, and mixed melting point with an authentic sample of the diphenylol methane as being the latter material. A sample was distilled and was shown to have a boiling point of 237-43 C./12-13 mm. and a melting point of about 159.5-16l.5 C. The literature reports a melting point of 162 C. for highly purified 4,4'-diphenylol methane. The yield of essentially pure diphenylol methane represented about 47.9% yield of product based on the amount of dimethylol urea originally employed.

This yield of purified product is many times that recorded by Megson and Drummond (J. Soc. Chem. Ind. 49, 251, 57T, 1930) who obtained 6.2 grams of diphenylol methane, that is 4,4- dihydroxy diphenyl methane upon reacting 2'70 grams of phenol and an equal molar quantity of paraform in the form of an alcoholic solution. This yield of product is also apparently many times that obtained by the patentee in German Patent 511,210 who only speaks of obtaining traces of diphenylol methane. In the latter instance, these products are seldom obtained, only one case being mentioned, and then only in a small quantity.

Example 2 1 In this example, grams of ZA-dimethyl phenol was dissolved in 30 cc. of glacial acetic acid and 5 cc. concentrated hydrochloric acid; The solution was heated for 80-90 C. and a solution of 3 grams of dimethylol urea in 25 ml. of water was added in small portions. The mixture was then boiled for minutes and upon cooling a solid separated. The aqueous layer was decanted and fresh water was added. The mixture was again heated to boiling and when the product was again cooled, copious amounts of crystals were formed. The crystalline mass was separated from the water by extraction with ether. The ether solution was dried and part of the ether evaporated. Upon adding petroleum ether, a snow white crystalline product separated. The product melted at 150-152 C. and was soluble in caustic solution. The sample was analyzed for carbon and hydrogen and found to contain 80.06% carbon and 7.86% hydrogen. The calculated values for a compound having the formula 011 on cm-Ocm-[j-om CH3 OH: is '7 9.90% carbon and 7.83% hydrogen. Zinke and Ziegler, Ber. 74B, 205-14 (1941) have prepared a compound described immediately above and reported a melting point of 148 C.

It will, of course, be apparent to those skilled in the art that other concentrations of the phenol, that is, of either the phenol itself or the 2,4-dimethyl phenol, based on the urea, may be also employed without departing from the scope of the invention. In addition to dimethylol urea one may also use monomethylol urea. Instead of using concentrated hydrochloric acid, other acidic type catalysts, many examples of which are mentioned above, may be employed in the quantity described above or in larger or smaller amounts. The conditions under which reaction is effected between the ingredients may, of course, be varied within wide limits without departing from the scope of the invention. Reaction may take place from room temperature to as high as -150 C.

Instead of extracting with water, it is possible, especially in the case when one of the reactants is 2,4-dimethyl phenol to use hot toluene as the extraction medium.

The diphenylol methane prepared in accordance with the present invention has many uses. Among these may be mentioned, for example, as an intermediate in the preparation of other compositions, specifically chlorinated derivatives thereof which have been found to have good insecticidal properties. In addition, the diphenylol methane may be caused to react with various aldehydic compounds, for example, formaldehyde, to make resins or resinous compositions which have use in the molding and laminating arts.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. The process which comprises effecting reaction between a methylol urea selected from the class consisting of monomethylol urea and dimethylol urea. with phenol in the presence of an acidic type catalyst, the phenol being present in a molar ratio of at least 2.5 mols of phenol per mol of methylol group in the methylol urea, and thereafter isolating the diphenylol methane obtained thereby.

2. The process which comprises effecting reaction between phenol and dimethylol urea in the presence of a strong acidic type catalyst, the phenol being present in a molar ratio of at least 2.5 mols of phenol per mol of methylol group in the dimethylol urea, and thereafter isolating the diphenylol methane obtained thereby.

3. The process which comprises efiecting reaction between phenol and dimethylol urea in the presence of aqueous hydrochloric acid, the phenol being present in a molar ratio of at least 2.5 mols of phenol per mol of methylol group in the dimethylol urea, and thereafter isolating the diphenylol methane compound prepared thereby.

ROBERT W. MARTIN.

REFERENCES CITED FOREIGN PATENTS Country Date Germany Oct. 16, 1930 Number 

1. THE PROCESS WHICH COMPRISES EFFECTING REACTION BETWEEN A METHYLOL UREA SELECTED FROM THE CLASS CONSISTING OF MONOMETHYLOL UREA AND DIMETHYLOL UREA WITH PHENOL IN THE PRESENCE OF AN ACIDIC TYPE CATALYST, THE PHENOL BEING PRESENT IN A MOLAR RATIO OF AT LEAST 2.5 MOLS OF PHENOL PER MOL OF METHYLOL GROUP IN THE METHYLOL UREA, AND THEREAFTER ISOLATING THE DIPHENYLOL METHANE OBTAINED THEREBY. 